Brake System

Abstract

11.1 Braking fundamentals 11.1.1 The energy of motion and work done in braking (Fig. 11.1) A moving vehicle possesses kinetic energy whose value depends on the weight and speed of the vehicle. The engine provides this energy in order to accelerate the vehicle from a standstill to given speed, but this energy must be partially or totally dissipated when the vehicle is slowed down or brought to a standstill. Therefore it is the function of the brake to convert the kinetic energy possessed by the vehicle at any one time into heat energy by means of friction (Fig. 11.1). The equation for kinetic energy, that is the energy of motion, may be given by where Uk-VzmV 2 Uk = kinetic energy of vehicle (J) m = mass of vehicle (Kg) V-speed of vehicle (m/s) The work done in bringing the vehicle to rest is given by where Uw=Fs Uw = work done (J) F = average braking force (N) s = distance travelled (m) When braking a moving vehicle to a standstill, the work done by the brake drums must equal the initial kinetic energy possessed by the vehicle so that